B. Any injury or "nuclear property damage" resulting from the "hazardous properties" of "nuclear material," if:

1. the "nuclear material" (a) is at any "nuclear facility" owned by, or operated by or on behalf of, any Insured or (b) has been discharged or dispersed therefrom;

2. the "nuclear material" is contained in "spent fuel" or "nuclear waste" at any time possessed, handled, used, processed, stored, transported or disposed of by or on behalf of any Insured; or

3. the injury or "nuclear property damage" arises out of the furnishing by any Insured of services, materials, parts of equipment in connection with the planning, construction, maintenance, operation or use of any "nuclear facility," but if such facility is located within the United States of America, its territories or possessions or Canada, this Exclusion B.3. applies only to "nuclear property damage" to such "nuclear facility" and any property therein.

C. As used in this exclusion:

1. "Hazardous properties" includes radioactive, toxic or explosive properties.

2. "Nuclear facility" means:
   a. any "nuclear reactor";
   b. any equipment or device designed or used for
      (1) separating the isotopes of uranium or plutonium,
      (2) processing or utilizing "spent fuel" or
      (3) handling, processing or packaging "nuclear waste";
   c. any equipment or device used for the processing, fabricating or alloying of "special nuclear material" if at any time the total amount of such material in the custody of any Insured at the premises where such equipment or device is located consists of or contains more than 25 grams of plutonium or uranium 233 or any combination thereof, or more than 250 grams of uranium 235;
   d. any structure, basin, excavation, premises or place prepared or used for the storage or disposal of, "nuclear waste," and includes the site on which any of the foregoing is located, all operations considered on such site and all premises used for such operations.

3. "Nuclear material" means "source material," "special nuclear material" or by-product material.

4. "Nuclear property damage" includes all forms of radioactive contamination of property.

5. "Nuclear reactor" means any apparatus designed or used to sustain nuclear fission in a self-supporting chain reaction or to contain a critical mass of fissionable material.

6. "Nuclear waste" means any "nuclear waste" material (a) containing "by-product material" other than the tailings of "nuclear waste" produced by the extraction or concentration of uranium or thorium from any ore processed primarily for its "source material" content, and (b) resulting from the operation by any person or organization of any "nuclear facility" included within the definition of "nuclear facility" under Paragraph C.2.a. or C.2.b.

7. "Source material," "special nuclear material," and "by-product material" have the meanings given them in the Atomic Energy Act of 1954 or in any law amendatory thereof.

8. "Spent fuel" means any fuel element or fuel component, solid or liquid, which has been used or exposed to radiation in a "nuclear reactor."

This endorsement does not change any other provision of the policy.